package paths

import (
	"os"
	"path/filepath"
	"testing"
)

func TestResolveRuntimeDirPrefersEnv(t *testing.T) {
	t.Setenv("BANGER_RUNTIME_DIR", "/env/runtime")

	if got := ResolveRuntimeDir("/config/runtime", "/deprecated/repo"); got != "/env/runtime" {
		t.Fatalf("ResolveRuntimeDir() = %q, want /env/runtime", got)
	}
}

func TestResolveRuntimeDirUsesInstalledLayout(t *testing.T) {
	root := t.TempDir()
	runtimeDir := filepath.Join(root, "lib", "banger")
	createRuntimeBundle(t, runtimeDir)

	origExecutablePath := executablePath
	executablePath = func() (string, error) {
		return filepath.Join(root, "bin", "banger"), nil
	}
	t.Cleanup(func() {
		executablePath = origExecutablePath
	})

	if got := ResolveRuntimeDir("", ""); got != runtimeDir {
		t.Fatalf("ResolveRuntimeDir() = %q, want %q", got, runtimeDir)
	}
}

func TestResolveRuntimeDirUsesSourceCheckoutRuntimeSubdir(t *testing.T) {
	root := t.TempDir()
	runtimeDir := filepath.Join(root, "runtime")
	createRuntimeBundle(t, runtimeDir)

	origExecutablePath := executablePath
	executablePath = func() (string, error) {
		return filepath.Join(root, "banger"), nil
	}
	t.Cleanup(func() {
		executablePath = origExecutablePath
	})

	if got := ResolveRuntimeDir("", ""); got != runtimeDir {
		t.Fatalf("ResolveRuntimeDir() = %q, want %q", got, runtimeDir)
	}
}

func createRuntimeBundle(t *testing.T, runtimeDir string) {
	t.Helper()
	for _, rel := range []string{
		"firecracker",
		"customize.sh",
		"packages.apt",
		"rootfs-docker.ext4",
		"wtf/root/boot/vmlinux-6.8.0-94-generic",
	} {
		path := filepath.Join(runtimeDir, rel)
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
		}
		if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
			t.Fatalf("write %s: %v", path, err)
		}
	}
}